Needles, pins and other pointed articles rely on their points being sharp to achieve their various functions. For example, a sewing needle that is not sharp will not penetrate fabric easily and will require the application of additional force. Additional force may damage the fabric, damage the object applying the force (such as a hand), or damage the needle itself, potentially rendering it useless. The need to apply additional force may also slow down the sewing process.
When a needle, pin or other pointed article loses its sharpness, its user is faced with the choice of replacing or sharpening the pointed article. Replacing the pointed article has several drawbacks. Replacing can be seen as an inefficient use or even a waste of resources. More frequent replacement requires more elaborate disposal and resupply solutions. These disadvantages can lead to yet another—users may not replace the pointed article as often as they should for maximum effectiveness.
Sharpening a dulled pointed article avoids the most of the drawbacks of replacement. However, if the method or device used is expensive, difficult or tedious, users may not sharpen the pointed article as often as they should. Common hand tools such as files or sharpening stones may be used to sharpen a pointed article, but are often ineffective due to the small size the pointed article. Rubbing a small pointed article such as a needle on a file or other sharpening surface will likely create an irregular point with flat spots that has very poor penetration qualities. Holding the needle and then rotating an abrasive surface around the point while applying uniform pressure is difficult to perform by hand and will also likely result in an irregular point.
Presently known art attempts to address these problems, but not with adequate success. The following represents a list of known related art:
Date ofReference:Issued to:Issue/Publication:U.S. Pat. No. 2,426,892Mayer et al.Sep. 2, 1947U.S. Pat. No. 2,766,644MarksOct. 16, 1956U.S. Pat. No. 3,468,068SpruellSep. 23, 1969U.S. Pat. No. 2,465,442GaylorMar. 29, 1949U.S. Pat. No. 4,069,528Newton et al.Jan. 24, 1978U.S. Des. Pat. No. D297,209CohenAug. 16, 1988U.S. Des. Pat. No. D337,253GlesserJul. 13, 1993U.S. Pat. No. 2,657,503GainesNov. 3 1953U.S. Pat. No. 4,991,355GilesFeb. 12, 1991U.S. Pat. No. 3,092,081FraserJun. 4, 1963
The teachings of each of the above-listed citations (which do not themselves incorporate essential material by reference) are herein incorporated by reference. None of the above inventions and patents, taken either singularly or in combination, is seen to describe the instant invention as claimed.
U.S. Pat. No. 2,426,892 to Mayer et al. for a “Fishhook sharpener” issued Sep. 2, 1947 discloses a tapered recess used to receive a point for sharpening. With continued use the tapered recess will shortly abrade into a shape unable to support the sharpening process by allowing the point of the object to be sharpened to hit the bottom of the tapered recess, thus dulling the point. In addition, use of an abrasive material as disclosed in this reference will breakdown very quickly thus preventing the creation of a clean, sharp, crisp point.
U.S. Pat. No. 2,766,644 to Marks for a “Sharpening tool” issued Oct. 16, 1956 discloses using a coarse file section held in place against a “V” groove creating an inwardly extending slot having a tapered opening in which to place the objects point for sharpening. The problem with this design is the coarse file or abrasive section will create grooves in the needle or other type object causing stress fractures and failure under load conditions. Additionally, the “V” groove and abrasive plate relationship create a pinch point that will not allow the point to sharpen fully and will pinch, grip, and twist off the thin point as it is sharpened. Also, there is no provision for the expulsion of metal particles, abrasive particles, and broken tips as they are generated in the course of using this sharpening device. This will impede the successful sharpening of any object.
U.S. Pat. No. 3,468,068 to Spruell for a “Fishhook sharpener” issued Sep. 23, 1969 discloses the use of an abrasive conical socket in an attempt to create a method of sharpening a conical fishhook point. The actual result will be the creation of a dull fishhook conical point. There is nothing that prevents the hook point from rubbing on the bottom of the conical socket. Therefore, if a new fishhook were put through the sharpening process using this device it would be duller after the process than before using this device. Additionally, the complexity of design will create very expensive manufacturing costs for the task that it is capable of performing.
U.S. Pat. No. 2,465,442 to Gaylor for a “Phonograph needle sharpener” issued Mar. 29, 1949 and U.S. Pat. No. 4,069,528 to Newton et al. for a “Dart point sharpener and straightening device” issued Jan. 24, 1978 each disclose a “hone nest”—a cavity specially shaped to facilitate sharpening. The hone nest is designed to sharpen conical type points as with sewing needles, but can only sharpen a point that has the pre-sharpened exact shape of said hone nest. Given the various truncated and triangular shapes of the specialized sewing needles available and used today, this type of device is too limited as it is incapable of sharpening needle points of differing size and shape.
U.S. Design Pat. D297,209 to Cohen for a “Fishhook sharpener” issued Aug. 16, 1988 and U.S. Design Pat. D337,253 to Glesser for a “Ceramic blade and hook sharpener” issued Jul. 13, 1993 both show devices that are not easily used, requiring a high degree of eye-hand coordination skills for its use.
Complexity of design and material use are critical elements to consider in today's economy as it relates to manufacturing costs along with the current competitive nature of offshore manufacturing. U.S. Pat. No. 2,657,503 to Gaines for a “Fishhook sharpener” issued Nov. 3, 1953 shows a device of extreme complexity. The fact that it is a machined assembly makes the manufacturing costs prohibitive in today's economy. Despite its complexity, this device cannot dress a conical tapered point as required on many sewing needles and pins. It can only sharpen one surface area of the point, producing a spade or shovel type point.
U.S. Pat. No. 4,991,355 to Giles for an “Apparatus for sharpening points” issued Feb. 12, 1991 and U.S. Pat. No. 3,092,081 to Fraser for a “Sharpener” issued Jun. 4, 1963 disclose devices that are additional examples of products that are extremely expensive to manufacture. These devices are capable of sharpening a conical point on a stationary held object using reciprocating and rotary abrasive elements driven by a battery powered motor.
In summary, the art commented on above employs designs and materials that are marginal at best in performance, operation, and in some cases, useful product life. The wrong materials for the application and over complexity of mechanical design for the desired application can make these previous designs undesirable.